GG3 Cord Mod for Holding Upright and Backwards (HUB System) updated 10/20/24
- Mod needs to be easy to do
- Attachment point to the GG needs to be strong - not supported by plastic
- The angle that it hangs from the chest harness needs to be adjustable
- Cord needs to be kept away from the rope path and the GG handle which could interfere with lock-up
HUB System (assumes use with a springless GG or GG+ in TR mode)
Advantages
- Less possibility of high clip failure - quick and more positive lock up.
- GG is held higher and in a better position to pull slack for clipping. Especially handy for those with short ape index like me.
- Less tendency to flip over backwards because of chest harness however it’s still possible.
- Less flip-flopping around during a fall, thus reducing the length of fall - up to a foot less. This can be important if you are climbing on vertical or less terrain and there’s objective fall hazards.
- Can adjust the feed resistance (and thus back-feed) by adjusting angle of the GG with the HUB cord.
Disadvantages
- It most likely won’t hold a head first fall (unless backed-up - which I consider mandatory). Needs more testing though. Volunteers?! 😊
- May not feed as well traversing - needs more real world testing.
- Requires a chest/shoulder sling/harness which is a hassle and may take a bit of effort to get everything fine tuned.
- Can’t pull rope directly up for a high clip - it will lock instantly and short rope you (springless GG, and GG+). However, if you pull slack down, then clip-up, it works like a charm. Once learned this becomes natural. (It’s the same movement as pulling more slack for the cache loop if you are using that method). Many people who use the Inverted GG method also pull a slack loop down before clipping up and is the norm for a Soloist and an El Mudo
Discussion
Inverted GG (Hanging Backwards)
Advantages
- Potentially holds inverted falls
- Feeds fairly well in all orientations because it it free hanging and can orient itself to the direction of rope pull
- Can pull directly up to clip (depends upon rope pairing)
- Simpler setup - no necessary mods or chest harness
- Could be a slightly softer lock-up because of the strong spring
Disadvantages
- Takes longer to lock up because of it’s hanging orientation: needs to flip 180 degs and travel from the hanging to upright position
- Not as convenient to pull slack for those with short ape indexes. Have to reach down further to pull slack.
- Has proven not to lock-up on high clips or when sagging on rope without a significant jerk (as Yann Camus has demonstrated and others have experienced). It needs a significant fall/jerk on rope to lock-up because of the strong spring
- Depending upon rope pairing, it can lock-up unexpectedly while clipping.
Discussion
- only requires one hole to be drilled that doesn’t harm the function or integrity of GG
- holds the GG at a stable angle that is easily adjustable
- is always held by one or more connection points when swapping devices
- uses the cord connection to the ‘biner to help keep GG from cross-loading on the ‘biner
- GG is still functional for all normal uses
How to Make the GG HUB Mod (now called the HUBBY system 😊 - Held Upside-Down and Backwards Bridle Yoke)
- Drill a small 1/8” hole in cover at location shown This does not affect the GG in any way (strength or function).
- Chamfer the edge of the hole on both side so there are no sharp edges to wear on the cord. I used a larger drill bit tip to accomplish this along with a little piece of rolled up 220 emory paper.
- Insert one end of a 2.5 mm accessory cord through hole. (I have now transitioned to using 1.8mm polyester covered dyneema. It is more abrasion resistant and just as strong or stronger - see photos for GG+ near the end of the post)
- Put an overhand knot in it then burn the end so that there is a melted blob on the end that acts as a stopper.
- The cover of the GG fits loosely so there’s already clearance for the cord. However I sanded the plastic spacer to introduce a bit more clearance so it didn’t bind or rub on a sharp edge and allows the cover to easily open and close.
- On the other end (on ‘biner), I tied a Poacher's knot (half a double fisherman’s knot - see first comment below). This allows it to be loosened to put on the 'biner and then cinched down to help keep the GG centered and prevent cross-loading. The chest harness should also keep the GG upright mitigating cross-loading. (I have stopped using this in favor of a overhand loop on a bight. See description at end fo post)
- In the middle of the cord, I tied an overhand on a bight for connection point to the harness to hold it upright. The position of this will determine at what angle the GG hangs at. This will determine how well it feeds. There’s many variables depending upon whether it is an unsprung GG, a GG+ in TR mode or a GG with a normal strong spring. This will be unique for each rope/harness/GG setup and needs experimenting to find the angle for best performance.
Five ways to handle cache loop/back-up for HUB system
- Cache loops pre-tied cloves on ‘biners clipped to gear loops ala Brent Barghahn https://www.brentbarghahn.com/
climbing-blog/redpoint-rope- soloing-2021. Use keyless ‘biners and drop loops as needed. Use with a Metolius Super Safe harness or backup gear loops as shown in Brent’s blog. - Cache loop with Microtrax on ‘biner clipped around waist belt. Separate webbing loop with ‘biner near belay loop. Only tie back-up knot on it between MT and GG as needed for cruxes then drop the knot when passed the crux.
- ‘Biner around waist belt with a Klemheist tied around rope to manage cache loop and act as backup. If using this method you have to hold knot with teeth while pulling slack ala El Mudo.
- Back-up slip knots pre-tied before cache loop. Pull to undo as needed as it nears the Microtrax. Microtrax should be on full strength gear loop or backed up.
- Backpack method - backup slip-knots pre-tied at intervals then stuffed in a backpack. Cache loop is pulled/feeds from backpack and backup knots untie as they “appear” by grabbing with mouth and pulling with free hand.
- The
Current thoughts and experiments on using an unsprung Grigri using the HUB System
Current experimentation: Different ‘biners to connect the GG to harness and precautions to prevent cross-loading. How tight or loose the connection should be between chest harness and climbing harness via the GG and HUB cord. Currently, I try to adjust so that the weight is on chest/shoulder harness so it’s hanging as free as possible from the HUB cord. I use a large oval ‘biner to connect to the belay loop. This allows the ‘biner to slide up and down within the belay loop a bit which helps maintain the correct angle while moving around. If the unsprung GG gets into a horizontal position it will lock-up and prevent any upward motion, so beware!
Plastic spacer ground/filed/sanded slightly to increase clearance for 2.5mm cord |
Thirdly I've changed from using a Scaffold knot that can be cinched down on the 'biner to an overhand on a bight which makes it is easier to put on and take off. I've sized the loop to allow the bulk of the knot to clear the body of the GG which allows the tow loop connection to be better centered (see last photo in the composite above).
Lastly, I failed to show the beveled/chamfered cord hole in the inside cover of the GG. This protects the cord against the sharp edge of the hole. It is done by using a drill bit several sizes larger than the diameter of the hole with a small amount of pressure to remove the sharp edge of the hole and put a light bevel on it.
Note: While some of the photos show an aluminum locking 'biner, I normally used a rated stainless steel quicklink or a auto-locking steel oval or symmetrical pear 'biner.
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For a quick way to test the HUB (HUR) system with your particular GG/rope combo without drilling a hole, you can use a 1.0mm - 1.2 mm dyneema cord. Start with a piece that 3' or so. That's much more than is needed, but makes tying the knots so much easier. The final length of the HUB can be adjust in the knot in the last step.
- Wrap the cord around the cover plate's pivot axle and tie a Scaffold knot. Once the Scaffold knot is tied cinch it tight until the cord is worked down in between the cover plate and body. Depending upon how loose your cover plate is, it could take a lot of pressure pulling/tightening it around the axle.
- In the middle of the cord tie a clove hitch around the 'biner/clip that you will use to clip it to your chest harness
- Take the other end and tie a overhand on a bight which will be used for slipping over the 'biner.
- Before securing the bight, adjust the knot/bight for the desired length for hanging from your chest harness.
- Trim the excess cord from the ends and burn them.
- The hang angle can now be adjust by loosing the clove hitch and lengthening/shortening the relative lengths of the legs of the bridle.
The "sliding loop made with half a double fisherman’s knot" you discuss is called a Poacher's Knot (https://www.animatedknots.com/poachers-knot), aka Strangle Snare, Halyard Knot, Double Overhand Noose, or Double/Two-Turn Scaffold Knot.
ReplyDeleteIt is closely related to the Scaffold Knot, which (properly) has three turns and is also known as a triple overhand noose. The Scaffold Knot is often (improperly) used to the refer to the two-turn variation as well. The Scaffold Knot is commonly used in the arborist/caving/IRATA worlds for connecting a carabiner to the end of a rope. It holds the carabiner orientation nicely (minimizing chances of cross-loading), uses little rope, and comes untied easily (slide the biner out and the knot falls apart). It is also quite strong, but does have an incorrectly tied "death knot" version that is visually similar when dressed. See https://www.youtube.com/watch?v=e343To9hznU for pull-tests and death-knot variation discussion
Thanks for the info
DeleteThis is very useful information. I also have an unsprung GriGri and lead solo (usually Lov2). I have tried your setup and feel it is safer. Safer than Lov2 and Revo. I think this information should be shared with a wider audience. The cord configuration is very well thought out. Well done you!
ReplyDeleteThanks for the feedback. I shared this info on the FB rope solo group. I'm way behind but will post on SICgrips Instagram account also.
DeleteHi. How much are the disadvantages if I do this with a spring-intact GG3? I'm looking to try this for aid LRS, so will be fairly slow, small movement climbing.
ReplyDeleteSorry for the delayed response. I'm just learning how to approve and respond to comments. I'm not an aid climber so may not be the best one to address that. Having said that I would think the disadvantage is that it will not always lock-up if you high-clip and weight it - which seems to me to be what aid climbers do. If you weren't into disabling the spring, I would either get a GG+ and use the TR spring setting or buy a Petzl Grillon ($$) which is basically the same as a GG without a spring.
DeleteHola ! Excelente blog .Quiero usar un grigri clásico para top Rope . ¿Como puedo usarlo sin modificar resorte y con garantÃas de seguridad ? También he visto por la web gente que lo usa sin arnés de pecho y de primero.Gracias .
ReplyDelete